Physical impairment

Mobility is medicine: Staying strong in the ICU

Mobility Matters

Critically ill patients can develop profound weakness while in the ICU. It isn’t entirely clear why ICU patients seem to be at such high risk for acquired physical impairment (API) but inflammation, immobility, and the severity of a patient’s illness are probably very important factors. API contributes to prolonged need for mechanical ventilation, increased ICU and hospital length of stay, and can cause long term weakness, disability and decreased quality of life for ICU survivors.

The problem isn’t small. Up to 50% of patients develop significant weakness after their ICU stay. This weakness can last for years and prevents patients from returning to their normal activities. In follow up studies from surgical, medical, and trauma ICUs survivors of critical illness report having difficulty returning to work, lacking the energy and endurance they need to pursue their usual activities, and experiencing a reduced quality of life — all related to the weakness they developed while being in the ICU.

Patients expect an outcome from their illness that goes beyond surviving a disease or injury. They want to return to the life they led before they were admitted to the ICU. This requires strength, endurance, and the ability to move free from pain.

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Acquired Physical Impairment: A Deeper Look…

The term ICU-acquired weakness (ICUAW) has been used to describe neuromuscular weakness that is caused by critical illness itself. There are multiple terms used to describe the underlying pathophysiology of acquired weakness. These include Critical Illness Neuropathy (CIP – characterized by nerve damage affecting both sensory and motor nerves) and Critical Illness Myopathy (CIM – defined as muscle weakness with decreased or absent reflexes) and both are definitions of specific clinical assessments made when a patient who previously had normal strength develops an appearance of nearly full body paralysis without any underlying neurologic diagnosis.

In the most extreme cases, these patients can hardly lift their hand from the bed and cannot independently move their legs at all. Patients with this form of weakness are at higher risk for increased hospital length of stay and frequently require institutional care at discharge. They also are more likely to require prolonged mechanical ventilation and are at higher risk for mortality.

Who is vulnerable to developing API in the ICU?

The short answer: all ICU patients.

However, there is evidence that some populations are particularly high risk of developing weakness during their ICU stay. This includes patients who were previously sedentary or malnourished, those with chronic or long-term illnesses such as cancer, HIV, and chronic kidney or liver disease and patients requiring mechanical ventilation.

The importance of recognizing mechanical ventilation as a risk factor

Patients requiring mechanical ventilation during their course in the ICU are at increased risk for developing Acquired Physical Impairment. This may be due to a greater likelihood of requiring sedating medications and the immobilization that often results while on the ventilator, or an unclear metabolic process causing increased muscle protein breakdown. Studies examining the thickness and circumference of leg muscles in patients on mechanical ventilators show a dramatic decrease in the size and architecture of the large muscles in the thigh. Additionally, neuromuscular blocking agents may contribute to the development of weakness in the ICU especially when combined with steroid administration.

The Benefits of Mobility

Patients who receive physical therapy in the ICU are discharged from both the ICU and the hospital sooner, require mechanical ventilation for shorter periods of time, and are more likely to be able to take care of themselves and walk by themselves rather than going to a skilled nursing facility upon discharge. Furthermore, patients who receive physical therapy in the ICU report increased quality of life, physical function, and muscle strength, and are less likely to be readmitted to the hospital in the first year after being discharged. Learn more »

Timing Matters

Early mobilization is key. “Early” mobility means patients are engaged in physical activity very early in their ICU stay, ideally within the first 48 hours or as soon as they are stable. Physical therapists can help determine what activities are the most beneficial for each patient and may be consulted to assess and prescribe early activities and mobility for the patient soon after they are admitted to the ICU. Physical therapy in the ICU can involve anything from doing exercises in bed to ambulating.

Progressive Mobility

Each patient should perform the maximum level of mobility they are capable of each day. However, it is common for patients to regain their strength incrementally and they can benefit from any level of activity.

Bed Exercises– Whether performing simple ankle and leg exercises or moving toward sitting at the edge of the bed, these are great activities for increasing patient alertness and may help prevent DVTs.

Sitting at the edge of the bed– For patients who are deconditioned this may constitute exercise and, while it may seem very simple, it can help improve core and trunk strength and improve respiratory mechanics.

Moving toward standing– Assisting the patient to stand at the edge of the bed can help assess their balance, ability to support their own weight, and the stability of their trunk muscles. This is an important step toward being able to ambulate can build confidence and help the patient regain balance.

Sitting in a chair– In a chair, patients develop upright tolerance, give their vestibular system and cognition the correct sense of upright as normal, experience gravity as a force they can contend with, and it helps to restore the natural circadian rhythm. Prolonged sitting in a chair helps patients develop endurance for pulmonary hygiene and postural control to allow for progression to standing.

Walking with any level of support– Patients who can take a few small steps in place with support should walk in the ICU, particularly if they were walking within the week prior to admission. Walking is an ability that can quickly be lost as deconditioning sets in. It is much easier to prevent it from being lost than it is to regain the lost ability. Allowing patients to walk outside of their ICU room may further help by reducing delirium in exposing them to daylight at a window, and to the geography of their surroundings.